She was taking a walk with Moira and Cher, and their Pokémon, when Iris's Emolga bumped into Moira's Cinccino by accident. Soon, Ash, Iris, and Cilan showed up. She introduced herself with the other girls and laughed when Moira called Iris's Emolga and Ash's Snivy ugly. This made Iris furious, and she tried to chase after Mona and the other two. However, before Iris could catch them, they escaped in their RV.

Ash, Iris, and Cilan got into their club, having dressed up in real ladies attire, and Mona was the first person they saw while inside. Mona did not recognise them from earlier and was suspicious about the unknown guests, so they told Mona a lie, that they wanted to see the Flower Garden Troupe practice. Mona was still reluctant to let them proceed at first, but she asked Moira, who allowed them to see them practice.

Further inside the building, Moira, Mona, and Cher offered a competition against Iris, Ash and Cilan. They each faced off one on one by each choosing one Pokémon. One part of the competition involved having two chosen Pokémon stand on a balance beam with one trying to push the other into muddy water. Mona faced off against Iris and her Emolga, while she chose her Lilligant. Emolga was in danger of being defeated, but prevented herself from doing so by flying up. When Lilligant leaned over to push Emolga, she dodged it by again, causing Lilligant to lose its balance and fall into the muddy water, giving Iris the win. Mona was immediately shocked over this loss.

The next part of the competition had two Pokémon battle against each other in a regular battle. In the first battle, Mona battled Cilan's Pansage. Pansage attempted to dodge Lilligant's attacks by digging, but was ultimately hit with an Energy Ball. This knocked not only Pansage into the muddy water, but Cilan as well.

Like the other two girls, Mona has a very arrogant personality. An example of this is whenever she defeats someone, she laughs hysterically and rubs it in the Trainer's face. Iris mimicked this arrogance when her Emolga defeated her Lilligant, and made Ash and Cilan do so too. Like Cher, she seems to agree with everything Moira says.

Pokémon

Lilligant is the only Pokémon that Mona is known to have. While she was defeated by Iris's Emolga, she later defeated Cilan's Pansage. Lilligant was shown to be good in evading; she was able to easily dodge all of Pansage's Bullet Seeds.